Global Patent Index - EP 0634739 B1

EP 0634739 B1 2000-11-22 - Magnetoresistance effect magnetic head and composite magnetic head

Title (en)

Magnetoresistance effect magnetic head and composite magnetic head

Title (de)

Magnetowiderstandseffekt-Magnetkopf und zusammengesetzter Magnetkopf

Title (fr)

Tête magnétique à effet de magnétorésistance et tête magnétique composite

Publication

EP 0634739 B1 (EN)

Application

EP 94110906 A

Priority

  • JP 17401493 A
  • JP 21396393 A

Abstract (en)

[origin: EP0634739A2] A thin-film magnetic head, a magnetoresistance effect magnetic head and an MR inductive head are disclosed. The thin-film magnetic head has one of thin-film magnetic cores stacked on a substrate and formed of two magnetic films and a non-magnetic film held between them, with a current flowing through the thin-film magnetic core in the direction of hard axis thereof. The magnetoresistance effect magnetic head has one of a pair of shield cores having a magnetoresistive element between them formed of two magnetic films and a non-magnetic film held between them, the magnetoresistive element being electrically connected to the shield core, with a sense current flowing through the shield core. The current flowing through the one shield core via the magnetoresistive element is preferably an AC of decrement amplitude for demagnetizing the shield core along with a DC sense current. Also, this current preferably flows in the direction of hard axis of the shield core so that magnetic properties of the shield core are stabilized or demagnetized by the magnetic field generated in the direction of easy axis. The MR inductive head has a second thin-film magnetic core as a common magnetic body of an MR head and an inductive head on one substrate, formed of two magnetic films and a non-magnetic film held between them, with a current flowing through the second thin-film magnetic core in the direction of hard axis thereof. <IMAGE> <IMAGE>

IPC 1-7 (main, further and additional classification)

G11B 5/31; G11B 5/39

IPC 8 full level (invention and additional information)

G11B 5/31 (2006.01); G11B 5/39 (2006.01); G11B 5/465 (2006.01); G11B 5/02 (2006.01)

CPC (invention and additional information)

G11B 5/3967 (2013.01); G11B 5/3113 (2013.01); G11B 5/465 (2013.01); G11B 5/02 (2013.01); G11B 5/3906 (2013.01); G11B 5/3912 (2013.01)

Designated contracting state (EPC)

DE FR GB

EPO simple patent family

EP 0634739 A2 19950118; EP 0634739 A3 19970625; EP 0634739 B1 20001122; DE 69426318 D1 20001228; DE 69426318 T2 20010517; JP H0778309 A 19950320; US 5822159 A 19981013; US 5872691 A 19990216

INPADOC legal status


2003-05-02 [REG FR ST] NOTIFICATION OF LAPSE

2003-03-31 [PG25 FR] LAPSED IN A CONTRACTING STATE ANNOUNCED VIA POSTGRANT INFORM. FROM NAT. OFFICE TO EPO

- Ref Country Code: FR

- Free text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

- Effective date: 20030331

2003-03-05 [GBPC] GB: EUROPEAN PATENT CEASED THROUGH NON-PAYMENT OF RENEWAL FEE

- Effective date: 20020713

2003-02-01 [PG25 DE] LAPSED IN A CONTRACTING STATE ANNOUNCED VIA POSTGRANT INFORM. FROM NAT. OFFICE TO EPO

- Ref Country Code: DE

- Free text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

- Effective date: 20030201

2002-07-13 [PG25 GB] LAPSED IN A CONTRACTING STATE ANNOUNCED VIA POSTGRANT INFORM. FROM NAT. OFFICE TO EPO

- Ref Country Code: GB

- Free text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

- Effective date: 20020713

2002-01-01 [REG GB IF02] EUROPEAN PATENT IN FORCE AS OF 2002-01-01

2001-11-14 [26N] NO OPPOSITION FILED

2001-07-12 [PGFP FR] POSTGRANT: ANNUAL FEES PAID TO NATIONAL OFFICE

- Ref Country Code: FR

- Payment date: 20010712

- Year of fee payment: 8

2001-07-11 [PGFP GB] POSTGRANT: ANNUAL FEES PAID TO NATIONAL OFFICE

- Ref Country Code: GB

- Payment date: 20010711

- Year of fee payment: 8

2001-07-09 [PGFP DE] POSTGRANT: ANNUAL FEES PAID TO NATIONAL OFFICE

- Ref Country Code: DE

- Payment date: 20010709

- Year of fee payment: 8

2001-02-16 [ET] FR: TRANSLATION FILED

2000-12-28 [REF] CORRESPONDS TO:

- Document: DE 69426318 20001228

2000-11-22 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: B1

- Designated State(s): DE FR GB

1999-10-13 [RTI1] TITLE (CORRECTION)

- Free text: MAGNETORESISTANCE EFFECT MAGNETIC HEAD AND COMPOSITE MAGNETIC HEAD

1999-09-08 [RTI1] TITLE (CORRECTION)

- Free text: MAGNETORESISTANCE EFFECT MAGNETIC HEAD AND COMPOSITE MAGNETIC HEAD

1998-04-15 [17Q] FIRST EXAMINATION REPORT

- Effective date: 19980302

1998-01-14 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 19971114

1997-06-25 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A3

- Designated State(s): DE FR GB

1995-01-18 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A2

- Designated State(s): DE FR GB